In an energy storage apparatus provided with one or more energy storage devices, there has been known the configuration in which a gas is discharged to the outside from a discharge valve provided to each energy storage device.
For example, JP-A-2013-196851 discloses an energy storage apparatus which includes: a battery accommodating body; a power conditioner; and a housing which accommodates the battery accommodating body and the power conditioner. In such an energy storage apparatus, a ventilation port provided with a waterproof ventilation film is formed on a bottom portion of the housing, and the inside of the housing communicates with outside air through a waterproof ventilation film. With such a configuration, when an unpredictable phenomenon such as natural disaster or fire occurs, a combustible gas generated in the housing can be discharged to the outside through the ventilation port.
An energy storage apparatus for power storage use or power source use is used in various regions and conditions. From viewpoints of manufacturing efficiency, a manufacturing cost and easiness of installation or maintenance, it is not desirable that the structure of the energy storage apparatus becomes complicated.
As described in JP-A-2013-196851, when the waterproof ventilation film is mounted on the ventilation port of the housing, it is necessary to select a material such as a resin porous film sheet which forms the waterproof ventilation film. Further, an operation such as working of the material and fixing of the waterproof ventilation film to a ventilation port become necessary. When a through hole is simply formed in the outer case for discharging a gas, which has discharged from an discharge valve of the energy storage device, from the outer case which accommodates the energy storage device, there is a possibility that a foreign substance such as rainwater flows into the inside of the outer case through the through hole.